Today, in our environmental science lecture, we'll discuss urban heat islands. As you know, cities tend to be warmer than surrounding rural areas due to concrete and asphalt absorbing heat. However, one effective mitigation strategy is increasing green spaces, such as parks and green roofs. A recent study in Melbourne found that adding tree canopy can reduce surface temperatures by up to 8 degrees Celsius. But, interestingly, the study also noted that the cooling effect is strongest within 100 meters of the green area. Therefore, planners should distribute small parks throughout neighborhoods rather than concentrating them in one large central park.